


Loyalty and Cunning: The Start of Something New

by Eltuine



Series: Loyalty and Cunning [3]
Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: Alternate Universe - Fusion, Developing Relationship, Fluff, Friendship, Jealousy, M/M, Pre-Slash
Language: English
Status: In-Progress
Published: 2013-08-22
Updated: 2014-03-28
Packaged: 2017-12-24 07:43:15
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 5,455
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/937352
Author URL: https://archiveofourown.org/users/Eltuine/pseuds/Eltuine
Summary: <blockquote class="userstuff">
              <p>John and Sherlock enter their sixth and fourth years at Hogwarts, respectively. Things are a little different at the castle this year, though, what with three-headed dogs hidden in forbidden corridors and the possibility of something sinister reemerging. Sherlock's been acting stranger than usual lately as well, and it's up to John to figure out what's going on.</p>
            </blockquote>





	1. The Return Journey

**Author's Note:**

> The second story in my Potterlock series. It's not necessary to read the first, but things might make more sense that way.
> 
> As always, I own neither Harry Potter nor Sherlock. Please enjoy!

John was thrilled to be heading back to Hogwarts for his sixth year. It was a little bittersweet to be leaving his first-ever girlfriend behind when he went, but he'd missed magic so much that it had ached. It was the same every summer. After the months surrounded by paintings that spoke and staircases that moved, being back in his childhood, muggle home, barred from performing any magic, felt strangely hollow. He was also looking forward to seeing Sherlock again. They'd met up briefly in Diagon Alley when they'd each gone to pick up new books and other school supplies, but John had only been able to stay for an hour or he'd have missed his ride home, so he was too busy running around shopping to really catch up.

Steam billowed around his feet as he stepped through the barrier to the platform, and he couldn't help breaking into a grin at the familiar sight. Families of witches and wizards crowded the platform, all there to see children off to the only school of witchcraft and wizardry in the UK. John scanned the crowd, searching for familiar faces, or rather, one familiar face in particular. He was still thrown when he found Sherlock, despite having seen him only five days previous.

The skinny little kid that he'd befriended the year previous had grown like a weed over the summer, shooting up almost four inches. Whereas before, John had dwarfed the younger boy, it was now almost a dead heat, and John feared that he would soon be towered over by his friend.

"Sherlock!" He called out as he approached, catching the boy's attention. He turned to see John, and beamed with a rare smile. The rather rotund young man standing next to him surveyed John intently.

"John," Sherlock greeted him, "managed to get here alright, I see." John smiled at his friend. The older wizard cleared his throat, and then stepped forward, holding out his hand to shake John's stiffly.

"Mycroft Holmes," he introduced himself, "you must be the John that Sherlock has spoken of for the majority of the summer." Through the corner of his eye, John saw Sherlock's cheeks flush pink. "Going into sixth year, I see," Mycroft continued, "planning to be an Auror or a Healer. Hmm, both worthy professions, though vastly different from one another." John didn't even bother asking how Mycroft knew all of this. Either Sherlock had told him, or he'd used the massive Holmes intellect to deduce it all.

"It's good to meet you," John said, "Sherlock's told me all about you." Mycroft's eyebrows rose, and Sherlock smirked.

"Has he?" the elder Holmes asked rhetorically, "I wonder what, exactly, he's had to say." He eyed Sherlock knowingly, and John had to cough to cover up a laugh.

"Shame we haven't time to go over it all," Sherlock snarked, "we'd best be boarding."

"Have an excellent fourth year, brother dear," Mycroft said, practically oozing smarminess, "do try not to get expelled." 

Sherlock returned the jab in equal measure. "Best of luck with the diet, Mycroft. Don't exert yourself terribly behind your desk at the ministry." He swept off in a swirl of robes, leaving John standing by awkwardly, unsure what to say.

"Er, nice meeting you," he offered, "I'll keep an eye on Sherlock."

"You do that," Mycroft replied, and John had a difficult time discerning whether or not it was sarcasm. Shrugging, he turned to follow Sherlock onto the train.

On board, Sherlock had already staked a claim on a compartment, and John dragged his trunk into it, opening the door to Aengus's cage to allow the little burrowing owl to explore.

"Blimey, I still can't believe how much taller you are," John said as he flopped down into a seat. Sherlock's mouth twitched upwards.

"It's a miracle I grew at all, what with having to compete with Mycroft for food." 

"Sherlock," John admonished, "you shouldn't tease him about his weight." 

Sherlock sighed. "Very well. I'll tease him about his toadying and his repellant sartorial taste. Better?" John couldn't hide his chuckle.

"You're incorrigible." Sherlock smiled at that, and both boys began to talk about their summers. John eagerly shared the news of his very first relationship (though Sherlock didn’t seem terribly interested) and Sherlock told all about his experiments with poisons. He was just explaining how he'd managed to obtain ricin while avoiding being put on the muggle government's watchlists, when the door to their compartment flew open, a frantic first year on the other side.

"Sorry to bother you," he stammered, "but have either of you seen a toad? He- he's gone missing, and..." John shook his head.

"No, sorry. We haven't. If we do see him, we'll let you know." The boy nodded dejectedly, and closed the door. Sherlock rolled his eyes. "Poor kid," John said, "I remember being pretty scared during my first train ride. Good god though, was I ever that little?" Sherlock snorted, and both boys began laughing. 

“I suppose I’m a wise upperclassman now,” John said, “I’ll have to advise all the younger students on how to live their lives and what proper witches and wizards should behave like.” 

Sherlock groaned, “Please don’t. One Mycroft is horrible enough.”

“Is he really that bad?” John asked.

“He’s worse,” Sherlock said, “And he’ll only get more insufferable with time.”

“He works for the Ministry, doesn’t he? What does he do?”

“Right now, he’s some sort of under secretary of magical transportation regulation, but if he has his way he’ll be controlling the whole Ministry before he hits 26, and then the entirety of British Parliament by the time he’s 30.”

John scrunched his eyebrows together. “Can he do that? I don’t think even the Minister for Magic controls muggle politics.” Sherlock huffed.

“His goal is nothing so plebeian as Minister for Magic. He’ll invent his own position, give himself a cover title, and then operate from the shadows like some great umbrella-toting bat. I suspect I’ll have to move out soon so that I don’t get smothered by smugness.” 

John rolled his eyes at his friend’s theatrics. “Enough about your brother. Tell me about which courses you’ll be in.”

Unsurprisingly, Sherlock was taking ten courses, including O.W.L. level Transfiguration and (baring his final examination score) sixth year Potions. John hadn’t yet received his marks for his own O.W.L.s yet, so he didn’t know which courses he’d be in. He was hopeful, though.

They were soon joined in their car by Gabriel Truman, who had been patrolling about on Prefect duty, and Cedric Diggory, who wasn’t overly fond of Sherlock, but put up with him for John’s sake. Upon arrival at Hogwarts, the four boys piled into one of the horseless carriages together, and then into the Great Hall. Sherlock looked unhappy about having to sit at the Slytherin table - John knew he wasn’t terribly popular amongst his housemates - but had no choice, at least not on the night of the Start-of-term Feast.

“I’ll see you later, Sherlock,” John said, giving his friend’s shoulder a squeeze. The corner of Sherlock’s mouth quirked up, and he turned to head to his own table.

“You know who’s first year this is, don’t you?” Gabriel asked once they were seated. John shook his head. “Harry Potter!” John’s eyebrows rose.

“Blimey,” he whispered, “Don’t suppose he’ll end up in Hufflepuff though, eh?” Gabriel shook his head.

“Nah, probably Gryffindor. Still, pretty cool to have The Boy Who Lived at the same school as us, eh?” John nodded, and then their conversation was hushed by the arrival of the ghosts, and the Sorting Hat’s speech.

“God, I hate these songs,” Gayle, a fourth year, whispered, “We always sound like a bunch of losers when it gets to the Hufflepuff verse. Might as well just sing ‘Hufflepuff - they’ll take the rejects none of the other houses want!’” John bit his lip to hold back from smiling, and nodded. She had a point. Hufflepuff was almost more maligned than Slytherin in some regards, though for much less dark reasons. Gabriel shushed them both, and they watched the sorting begin.

Every student added to the Hufflepuff table was given a hearty round of applause, and then a murmur went up through the hall when McGonagall called out “Potter, Harry”. Unsurprisingly, he ended up in Gryffindor, with the entire table erupting into cheering so enthusiastic that it took almost a full minute before the ceremony could continue. Finally it was all over (John’s stomach had started growling by that point) and Dumbledore’s unusual speech was all that was left before they could start to eat.

John ate until he thought he might burst, and then managed to find room for dessert. By the end of it all, he was practically in stitches laughing while Gabriel tried to convince him to eat one more mint.

“But sir, it is only wafer thin!” Gabe plied in an atrocious French accent. John held his sides.

“Oh god, stop. I’ll vomit!” 

“Oh sir, it’s only a tiny little thin one!” 

“I’m serious Gabe! I will vomit all over you, and you’ll have to lead the first years to the common room whilst covered in partially digested shepherd’s pie and pudding!” Both boys dissolved into laughter.

~x~

Dumbledore’s little announcement at the end of the meal was certainly odd, and John couldn’t resist a glance over at Sherlock. True to form, the younger boy looked positively delighted at the possibility of investigating a corridor that could bring about a “very painful death”. John sighed. There was no way that this would end well.

Sure enough, not ten minutes after arriving at the Hufflepuff common room, John received a letter from Sherlock, care of Aengus (who refused to sleep in the Owlery, as he much preferred to burrow into the covers by John’s feet). 

**John,**

**Meet me at 1 AM, next to the statue of Gunhilda of Gorsemoor. Could be dangerous.**

**Sherlock**

John considered showing a prefect the letter and letting Sherlock get caught to keep him out of trouble. For all of thirty seconds. Then he set an alarm for 12:30, and got ready for bed.

Sneaking around through the halls of Hogwarts was an interesting exercise in stealth. On three separate occasions John had to duck into an empty room to avoid patrolling prefects and even one professor. By the time he made it to the right statue, it was almost 1:15. Sherlock was waiting for him.

“About time!” the Slytherin boy hissed, “I almost went investigating without you!” 

John rolled his eyes. “You do realise that this is a _terrible_ idea, right? When Dumbledore says something will end in painful death, he probably means it.” 

Sherlock waved his hand. “Yes, yes. I’m sure it’s nothing the two of us can’t handle. Shall we?” John sighed, but let Sherlock lead the way. 

The door to the third floor corridor was locked, and it was eerily silent outside. Sherlock knelt down and examined the floor.

“Hmm, some sort of magical creature’s been brought through here. Large, four-legged... John, can you hear that?” Both boys stilled and listened. From the other side of the door, John could hear what sounded like very heavy breathing.

“What _is_ that?” John hissed. Sherlock held up a hand in silence, and continued listening.

“Multiple simultaneous intakes of breath, but only one respiratory system...” he muttered, deducing what was being kept on the other side of the door, “It’s some sort of multi-headed animal. Fascinating! What could it be here for?” John was growing increasingly uneasy.

“Well, whatever the reason, I’d rather that _it_ stay on _that_ side of the door, while _we_ stay on _this_ side. Okay?” Sherlock pouted.

“You’re no fun at all.” John did his very best to look stern. “Ugh, fine! Fine. I’ll leave the door locked. For now.”

“Good,” John affirmed, before turning to head back towards the basement, “Now, we need to arrange another Patronus lesson. You’re going to manage a corporeal one before Christmas even if it means weekly sessions.” Sherlock smiled, and followed his best friend downstairs.

~x~

John was given his grades and timetable the next day. Somehow, he’d managed to pass every single one of his O.W.L.s, though he received only an A in History of Magic and Astronomy. That still left him with a very full time table, consisting of Defense Against the Dark Arts (in which he’d scored an O), Potions (another O, thanks to Sherlock), Transfiguration (E), Charms (E), Herbology (O), Care of Magical Creatures (E, though it would have been an O if he hadn’t tripped and gotten his robes singed by a fire crab), and Muggle Studies (E, because he hadn’t really bothered to try).

“Excellent job, Watson,” Professor Sprout congratulated him, “I look forward to seeing you in Herbology this year. Keep up the hard work!” John grinned and thanked the professor, before hurrying off to find Sherlock, who had been waiting outside of the Hufflepuff basement.

“I got an O in Potions!” he exclaimed, grabbing his friend into a hug. Sherlock flailed his arms until John let go, and then straightened his robes in an attempt to appear dignified.

“I’m not surprised. You’re not nearly as much of an idiot as most people are.” That was high praise, coming from Sherlock. “I’ll see you in class, then.” He smirked.

“You got an O, too? Congratulations!” John cried, pounding the younger boy on the back, “You must be the youngest student ever to take sixth year Potions!” Sherlock preened, and both boys headed into the Hufflepuff common room, discussing their plans for the year.


	2. Halloween in the Dungeons

**Summary for the Chapter:**

> _By the time Halloween rolled around, Sherlock still hadn’t told John what he was doing, but the older boy had gotten used to his friend’s eccentricities, and was content to wait it out until Sherlock was ready to share._
> 
>  
> 
> Sherlock is hiding something, and John can't figure out what. The arrival of a troll at Halloween causes a bit of a panic.

**Notes for the Chapter:**

> Possible mild trigger warning: Claustrophobia.

September passed quickly, with John becoming increasingly busy with all of his schoolwork, though he made sure to take time to write to Sarah once a week (via his mother, who made sure not to mention that the letters arrived by owl). Sherlock, however, started to disappear for hours on end without telling anyone where he was going. At one point, the boy was two minutes late for Potions class, earning a glare from Snape and a word of warning about consequences should he be tardy again (had it been anyone else, there definitely would have been a detention given out). Finally, after the fifth dinner where Sherlock was conspicuously absent, John confronted his friend.

“What are you up to?” he asked, cornering the dark-haired boy after Potions. Sherlock did his best to appear haughty and aloof.

“I don’t see why it’s any concern of yours.” John tried not to look hurt; he knew his friend didn’t mean anything by it.

“You’re my _friend_ , Sherlock. If you’re off getting yourself into trouble, I want to know what you’re up to! Maybe I can help? Please tell me you’re not still sneaking around the third floor corridor.”

“What, that?” Sherlock asked, “Oh, I figured that out ages ago. Three-headed dog. Guarding something. Dull. I have much more interesting things to focus on right now.”

“Three-headed- wait, what? What on earth could be more exciting than a three-headed dog!?” He was almost terrified of what the answer might be.

“I can’t tell you,” Sherlock answered cagily, “Not until I’m sure it’ll work.” John must have had a suspicious look on his face, as Sherlock sighed and attempted to reassure him. “Oh, calm down John. It’s nothing terrible, and no more dangerous than anything else we’ve done.” With that, he turned and left for Charms class.

“That’s what I’m afraid of,” John muttered to himself.

~x~

By the time Halloween rolled around, Sherlock still hadn’t told John what he was doing, but the older boy had gotten used to his friend’s eccentricities, and was content to wait it out until Sherlock was ready to share. That evening, the Slytherin boy popped over to the Hufflepuff table before the feast started.

“Any chance you’re gonna tell me what you’ve been up to?” John asked by way of greeting. Sherlock gave him a rare smile.

“Not just yet. I’m going to the dungeons now. Meet me after dinner, outside dungeon five? I want to go over the best methods for Draught of Living Death again.” 

“You’re not going to eat?” 

Sherlock shook his head. “Digestion slows my mind down too much. You’ll be there?” 

John nodded. “Sure, Sherlock. Is everything okay, or-”

“Great, see you there.” Sherlock hurried off before John could finish his sentence, leaving the Hufflepuff boy to stare quizzically after his friend.

John was just starting in on his second helping of potatoes au gratin (thank goodness for Quidditch practice or he’d be huge) when Professor Quirrell burst into the Great Hall, yelling about a troll in the dungeons.

 _The dungeons?_ John thought frantically, _Sherlock’s down there!_ He had to do something! He followed along with the other Hufflepuffs towards their common room in the basement, but quickly ducked away from where professors and prefects were herding the students once they reached the stairs, using the chaos as cover. The entire way down to the dungeons, all that he could think was _SherlockSherlockSherlockSherlockSherlock_.

A year of friendship with a Slytherin had left John with a pretty solid grasp of the layout of the Hogwarts dungeons, and all of the little passageways and side routes that could be used to get there. He hurried through an alcove, behind a tapestry, and then around a corridor, easily avoiding the group of professors who had gone off to do battle with the troll. He skidded around the corner, and ran to the door to dungeon five, listening carefully for any signs of human - or troll - therein. It was silent.

Carefully, John eased the door open, wand at the ready, afraid of what he might find. The room was empty. 

“Son of a _bitch_ ,” John hissed, stepping into the vacant classroom. He ran his hand through his hair, trying to figure out what to do next. Should he find the professors and tell them that Sherlock was off somewhere in the dungeons (without permission), potentially alone against a troll? Run around trying to find his friend? Pull out all of his hair? Option C looked like it might just happen regardless. “Damn you, Sherlock Holmes,” he whispered aloud. A sudden noise startled him, and he whipped around to see who was there, a stunning spell on the tip of his tongue. What he saw was not what he had expected.

Perched on the edge of a shelf was a falcon of some sort, a little over a foot tall, with a reddish-cream belly, an almost-black back and head, and pale, pale eyes. It was staring very intently at John.

“Oh!” he breathed, “Hello! Are you an escaped Transfiguration lesson? Were you previously a teacup or something?” The bird ruffled its feathers indignantly and glared (could birds glare?). “Sorry, sorry. Not a teacup, then.” John stared at the bird for another moment (and was stared at in return) before coming to his senses. “Right! Well, if you’ll excuse me, I have to go find my best friend and stop him from being eaten by a rampaging troll.” He turned and eased back out of the room, checking the corridor for teachers, and started to creep carefully through the dungeons, keeping an eye out for any signs of Sherlock.

Thankfully, less than a minute later, the two boys ran into each other - almost literally.

“Sherlock!” John cried, “God, I’m so glad I found you! There’s a troll loose in the dungeons! C’mon, we’ve got to get somewhere that’s _not here!_ ” Wordlessly, he grabbed his friend’s hand and began dragging him up towards the Hufflepuff basement.

“John,” Sherlock protested, “John calm down!”

“I will not ‘calm down!’” John growled, “You could have been killed! You could have been torn apart and eaten by a troll! I never would have seen you again!” He knew his voice was frantic, but he couldn’t bring himself to care. Sherlock dug his heels in and forced his friend to stop.

“John! Look at me.” John did so, staring wide-eyed at the other boy. “I. Am. Fine. Besides, there’s no troll in the dungeons. Have you ever _smelled_ a troll? Or heard one? They’re not exactly built for stealth. There’s no way that one could _possibly_ have gotten in and not been found by now, especially with the majority of Hogwarts’ faculty roaming around looking for it!”

Whatever John might have said in response was silenced by a shout from down below, and a thundering of footsteps up the stairs.

“Shit!” John hissed, “Quick, behind that armoire! Hide!” He pushed Sherlock bodily along, and squeezed into the small alcove after him, hoping that they hadn’t been spotted. At least two professors ran by, and John caught a snippet of the teachers’ conversation.

“...in the girls’ bathroom, though I don’t know why it wouldn’t be where he...”

He waited breathlessly for the professors to pass, and then remained hidden, crammed into the small space, unsure if any more would be coming by. John looked over at Sherlock, and saw that the boy was clenching his fists and had his eyes shut. John’s eyebrows knit together with concern. Was his friend in pain? He seemed to be muttering something under his breath. 

“Sherlock?” John whispered almost noiselessly, and the other boy’s eyes flew open. “What is it? Are you-” he was cut off by Sherlock hurtling out from their hiding place. John quickly followed, and found his friend bent over, hands on his knees, breathing heavily. “Hey, Sherlock,” John said worriedly, placing a hand on his friend’s shoulder, “What’s wrong?” Sherlock flinched away from the contact as if he’d been stung, and John removed his hand quickly. He stood silently, waiting for some sign as to what was the matter, trying to see if the boy had been injured somehow. After several more deep breaths, Sherlock straightened up, and tugged his robes properly into place.

“My apologies,” was all that he said before turning as though to make his way back to the Slytherin common room. John grabbed the sleeve of his robe and brought him up short.

“What the hell, Sherlock? What was all that about?” Quite frankly, John was getting sick of being kept in the dark all the time. Sherlock refused to meet his eyes. 

“It’s nothing, don’t worry about it.” His tone was small and closed off, and John instantly felt ashamed for getting angry. He cautiously placed his palm against Sherlock’s arm.

“Hey, look at me,” Sherlock’s eyes slid up to John’s face, but he kept his head down. “You don’t need to be embarrassed. I’m not going to judge you. I’m your friend. Is there anything I can do?” Sherlock shook his head, still silent. “Are... are you claustrophobic?” He nodded miserably, averting his gaze once again. “Oh, Sherlock...” John breathed, “Why didn’t you say something?” 

The younger boy scowled. “I don’t want your pity.” 

John frowned. “It’s not _pity_ , Sherlock. It’s... I dunno, concern! Friendship! Come on, let’s get out of the hallway so we don’t get caught by Filch or someone.” They walked together to the Hufflepuff basement, not speaking, and then into the common room. Gabe gave John a look that said “I should definitely give you detention for this” but said nothing. 

“Come on,” John said, “we can talk in the dorm.” He led the way up, and was relieved to find the sixth-year dormitory empty, the majority of the students waiting in the common room for news about the troll. He sat on his bed, and indicated for Sherlock to do the same. “Now, you don’t have to explain the whys or the whens or anything, but Sherlock... I’m your friend, right?” The younger boy looked startled to have even been asked.

“Of course, John,” he replied fervently.

“Well, friends don’t need to keep stuff like that from each other. There’s nothing wrong with being afraid of something. You don’t need to try to hide it or be ashamed.” Sherlock looked apologetic.

“I’m sorry,” he murmured. John frowned. He wasn’t trying to make Sherlock feel guilty, he just wanted him to know that he had no reason to try to be something he wasn’t - or to try not to be something he was, as the case may be. 

“It’s okay,” he said, “I care about you, Sherlock.” The younger boy looked up again, his eyes wide. “Do you... do you want to talk about it?” 

Sherlock sat for a moment, and seemed to be considering. After several heartbeats, he spoke. “Not... right now. Later, perhaps.” John nodded, and gave him a reassuring smile. “I think I’ll head down and go to bed now. It’s obvious that the troll situation is under control.” He got up to leave, and then paused, and turned back. “And John?”

“Mm?”

“Thank you. For being my friend.” John smiled at him, and then Sherlock was gone.

It wasn’t until John was almost asleep that he remembered the unusual bird from the dungeons, and by that point he was too far gone towards slumber to care.


	3. Chapter 3

**Summary for the Chapter:**

> _Sherlock was not at the Quidditch match (which Gryffindor had won in a very unusual manner), nor did he show up for dinner. By the time nine o’clock rolled around, John was starting to worry that his friend had decided to go after whatever was being kept in the third floor corridor, and gotten himself eaten._
> 
> Sherlock is still being sneaky, but he finally lets John in a little.
> 
> Warnings for: Badly bastardized Latin. But to be fair, JK did it first.

**Notes for the Chapter:**

> I'm sorry it's been so long! I'm sort of like a tree, I think; I'm not very good at producing anything in winter. Now that it's finally starting to look like Spring again (Canada: where winter lasts 6 months of the year) I'm all inspired. Thank you for sticking around!

John was so busy with schoolwork that he nearly decided not to bother going to the first Quidditch match of the year - Gryffindor versus Slytherin - until Cedric had shown up, red and gold flags in hand (very few people from other houses cheered for Slytherin), and practically _dragged_ him out to the pitch.

“Come on, John!” the younger boy cajoled with a bright smile, “You can’t miss the very first Quidditch match of the year!” John groaned, but got up and pulled a jumper on to wear under his robes. He opted to remain neutral, in terms of which team’s colours to wear. He would be cheering for Gryffindor, and he was fairly certain that Sherlock wouldn’t really care, but he didn’t want to show up in front of his friend wearing the colours of his house’s rivals.

As it turned out, he needn’t have worried. Sherlock was not at the Quidditch match (which Gryffindor had won in a very unusual manner), nor did he show up for dinner. By the time nine o’clock rolled around, John was starting to worry that his friend had decided to go after whatever was being kept in the third floor corridor, and gotten himself eaten. His anxiety was interrupted, however, by Aengus landing on his knee with a little bump.

“What have you got for me?” John asked the little owl, taking the letter from his beak. He knew exactly who it was from. Inside, there was a short letter, and a thick, folded square of parchment. If John looked at it head on, it looked like a blank page, but when viewed out of the corner of his eye, it seemed as though there were letters floating just below its surface. He eyed it with mistrust, and read Sherlock’s little letter.

**John,**   
**Dungeon 4, 11PM. Don’t be late. Bring the parchment.**   
**SH**

“What on earth is he up to now?” John muttered to himself, but he couldn’t help the fond smile that spread across his face.

~x~

John was definitely getting better at sneaking around the castle late at night when everyone was supposed to be in bed. He wasn’t sure what this said about him or his friendship with Sherlock, but it was a handy skill to have. He managed to reach dungeon 4 with ten minutes to spare, but the other boy was already there, and he quickly dragged John into the room.

“Were you followed?” Sherlock asked hurriedly.

“What? No, I don’t think so,” John said, confused, “Who would be following me?”

“You never know. Can’t be too careful,” Sherlock answered. He shut the door behind John and locked it with his wand.

“You going to explain what’s going on? What’s with the blank parchment?”

Sherlock grinned. “It’s an idea I had. You know how it’s dreadful to send messages back and forth by owl? How it takes so long, and is ludicrously inefficient?” John nodded, confused. “Well, I’ve figured out a better system. Take out your parchment.” John pulled the little folded square out and opened it up to its full 5x8 size. Sherlock stuck his hand into the pocket of his robes and withdrew an identical piece of parchment, unfolding it as well, then a self-inking quill. “Watch carefully,” he said.

First, he wrote a short message on the parchment: **Sherlock is a genius**

"And he's so modest, too," John muttered, earning a glare. Sherlock turned back to the paper. Raising his wand, he pointed at the parchment and said, _“Occulta Literarum,"_ and the words disappeared from the page, only to appear on John's parchment a mere second later.

"Cool!" John exclaimed, "Sherlock, that's fantastic! You made these all by yourself? That's incredible!" The other boy's cheeks turned faintly pink.

"I like text-based communication, and it'll give us a way to speak to each other in real time when we're not in the same room. You can erase it like this: _Evanescere Scribens_." He tapped John's parchment and it went blank again. "As long as you don't know the words to use it, it'll just act like regular parchment. Still, try not to let a professor confiscate it. It would be a pain to have to make another one."

"Is this what you've been so secretive about lately? You've been busy working on these?" John asked.

Sherlock shifted nervously. "In part..." he answered. John frowned.

"What are you up to, Sherlock?" The other boy bit his lower lip and wouldn't meet John's eyes for a moment.

"I can’t tell you... I will, I promise John. Just... not yet."

"Are you in danger?" John asked.

"No."

"Is anyone else in danger?"

Sherlock sighed and rolled his eyes. "No."

"Is it illegal?" Sherlock was silent. "Sherlock! What have you done!?"

"It's nothing bad, I swear!" the younger boy said, “I just can’t tell you yet. Do you understand?” 

John really didn’t like it, but he nodded reluctantly.

Sherlock looked contrite. “Are you angry with me?”

John blew out a breath and ran his hand through his hair. “No, not really... I mean, am I thrilled that you’re keeping some big - potentially illegal - secret from me? No. But... I can’t _make_ you tell me. Just... if you’re in some sort of trouble, you’ll let me know? Please?”

Sherlock nodded, his eyes wide. “Of course.”

“So, is that it then? You dragged me down here in the dead of night, risking detentions for us both, to show me the messaging system you came up with? You could have just pulled me aside between classes, you know.” It was said with no small measure of fondness.

“The messaging system is supposed to be a _secret_ ” Sherlock sneered, “Besides, I also wanted to show you something.” He was biting his bottom lip, though John couldn’t tell if it was because he was nervous or trying not to smile. 

“It’s not a three-headed, person-eating ‘something’, is it?” john asked cautiously. Sherlock heaved a great sigh.

“ _No_ John, it’s not the three-headed dog from the Third Floor Corridor - although I have made some potential progress in discovering what it’s guarding - but that’s not what I want to show you. Here, stand back.” John knew better than to ignore a warning from his slightly-mad friend, and took a giant step backwards, and then watched as Sherlock got out his wand, cleared his throat, scrunched his face up and incanted, “ _Expecto Patronum!_ ”

What burst from the end of Sherlock’s wand was no incorporeal mist, but a full-fledged Patronus, in the form of some sort of hawk. It flew an entire circuit around the room before dissipating. 

“Sherlock! That’s brilliant!” John exclaimed, thrilled for his friend, who was beaming with a proud smile, “How long have you been able to do that?”

“Only about a week,” Sherlock answered, “And I still can’t get it to stay until dismissed, but it’s a definite improvement.”

“Absolutely! Is it some sort of hawk?”

“ _Falco pelegrinoides,_ ” Sherlock responded matter-of-factly, “A Barbary Falcon, sometimes argued to be a subspecies of _Falco peregrinus_ , the Peregrine Falcon. So, yes, technically, it is ‘some sort of hawk’.” John smiled warmly.

“Congratulations Sherlock, I’m really proud of you.” The other boy ducked his head, but wasn’t quite fast enough to hide his blush, which just made John smile wider before he continued, “Now, we both need to get back to our respective common rooms, yeah?” Sherlock grumbled, but agreed to comply, and with a clasp of each other’s shoulders, the two boys went their separate ways.

It wasn’t until John was lying in bed, almost asleep, that he realised: he had seen that bird before.


End file.
